In the oral cavity, indigenous bacteria are often associated with two major oral diseases; caries and periodontitis [H. Marcotte and M. C. Lavoie, Oral microbial ecology and the role of salivary immunoglobulin A, Micro Mol Bio 62 (1998) 71-109]. The diverse structures within the mouth (i.e. the tooth surface, subgingival space, and tongue) support several different microbial communities. The supragingival environment of the oral cavity is regulated by saliva, a complex mixture of water, electrolytes (e.g. sodium, potassium, calcium, chloride, magnesium, bicarbonate, phosphate), enzymes (e.g. lysozyme, lactoferrin, peroxidase), proteins (e.g. sIgA, glycoproteins etc.), vitamins, hormones, urea and nitrogenous products. The less accessible subgingival environment is bathed by the gingival crevicular fluid (GCF), a plasma exudate containing proteins, albumin, leukocytes, immunoglobulins, and complement.
Good oral hygiene requires that one sustain a healthy oral ecosystem. However, the boundaries between the soft mucosa and hard teeth are ripe for bacterial colonization (e.g. the gingival crevice or sulcus). The sulcus together with the area between the teeth (i.e. approximate surface), and the pits and fissures of the biting surface are not easily cleaned by brushing (i.e. mechanical friction). Microorganisms tend to colonize these areas to form dental plaque; a biofilm of microorganisms and salivary components. If not removed, plaque can lead to caries or periodontal disease (e.g. gingivitis and possibly periodontitis). Plaque and calculus can be removed with or without electrically driven hand instruments in the dental office. Calculus, a form of hardened plaque, forms along the gum line and within the sulcus leading to inflammation that can eventually lead to deep pockets between the teeth and gum and loss of bone that holds the tooth in place. Human periodontitis is associated with a widely diverse and complex subgingival microbiota [Daniluk, T., Tokajuk, G., Cylwik-Rokicka, D., Rozkiewics, D., Zaremba, M. L., and Stokowska, W., Aerobic and anaerobic bacteria in subgingival and supragingival plaques of adult patients with periodontal disease, Adv Med Sci 51: (2006) 81-85].
While there are commercially available water jet devices for dental cleaning, they are limited for the most part to the removal of debris. The pumps used in these units are often noisy, which can contribute to patient discomfort. Seating or mating the tip with the water jet is sometimes problematic leading to leakage and ineffective or less than optimal irrigation. While some devices have adjustable controls, many do not provide good control.
Sensing devices for diagnosing oral health and/or hygiene are currently either in the research and development stage or are formatted for use by trained professionals. Many devices are not user friendly and not suitable for day to day use by consumers.